Modern vehicle accessories include devices such as automatic windshield wiper operating systems. These systems include a rain or moisture sensor that determines when rain or other precipitation is present on the vehicle windshield and then signals the windshield wipers directly or through the vehicle's computer to operate accordingly. The moisture sensor, typically located on the inside of the vehicle windshield, operates by sending a beam of light from an emitter, directed at an angle against the windshield, the beam being at least partially reflected to a detector. When the windshield is in a dry condition, the reflected light has parameters that differ from light reflected when the windshield is in a wet condition. To maximize efficiency, the moisture sensor unit is placed very close to the vehicle windshield. To provide a predictable optical path for the emitted and reflected light beams (apart from the desired anomalies caused by the wet windshield) an optical coupler is commonly placed between the windshield and the moisture sensor and is affixed to both.
In some instances moisture sensor units and optical couplers are incongruent. Typically, the moisture sensor unit includes additional components that are not directly associated with the transmission and reflection of light, for example, an electrical coupler used in a system for sending and receiving electrical signals and these components are not overlapped by the optical coupler. The incongruence between the moisture sensor unit and optical coupler means that there is a gap or aperture between a section of the moisture sensor unit and the vehicle windshield when the moisture sensor is in position. This gap or aperture may allow the moisture sensor unit to move in a manner not in unison with the vehicle windshield and optical coupler when either the entire vehicle is vibrated or the moisture sensor unit is jarred. This dissonant motion creates misalignment of the projected and reflected light beam causing “false positive” readings for the presence of moisture on the vehicle windshield.
What is desired is a structural stabilizer to compensate for incongruence between a moisture sensor unit and any element, such as an optical coupler, located between the moisture sensor unit and the vehicle windshield.